Method for determining motion vector and macroblock type

1. A motion vector and macroblock type determining method, the method comprising: receiving a high frame-rate video stream having N frames; skipping a frame N- 1 ; allocating a motion vector to a macroblock of frame N according to a macroblock type of the skipped frame N- 1 ; determining a macroblock type of the skipped frame N- 1 when the macroblock of the frame N is an intra type; allocating a macroblock type to a macroblock type of frame N according to a macroblock type of the skipped frame N- 1 ; wherein allocating the motion vector comprises: allocating an infinite motion vector to a macroblock of the frame N when the macroblock of the skipped frame N- 1 is an intra type; allocating a motion vector of the macroblock of the frame N when the macroblock of the skipped frame N- 1 is a skipped type; and allocating an approximated sum of the motion vector allocated to the macroblock of the frame N and the motion vector allocated to the macroblock of the frame N- 1 as a new motion vector for the macroblock of the frame N when the macroblock of the skipped frame N- 1 is an inter type; and outputting a low frame-rate video stream.

2. The method of claim 1 , wherein the macroblock type of the frame N is divided into an inter type and a skipped type.

3. The method of claim 2 , wherein the motion vector of the macroblock of the frame N is determined according to the macroblock type of the skipped frame N- 1 when the macroblock of the frame N is the inter type.

4. The method of claim 2 , wherein the macroblock type of the frame N is determined according to the macroblock type of the frame N- 1 located at approximately similar position with the macroblock of the frame N when the macroblock of the frame N is the skipped type.

5. The method of claim 4 , further comprising: determining a new motion vector of the macroblock of the frame N when the new macroblock is the inter type.

6. The method of claim 5 , wherein the new motion vector of the macroblock of the frame N is determined so as to be same with a motion vector of the macroblock of the frame N- 1 located at approximately a similar position with the macroblock of the frame N.

7. A motion vector and macroblock type determining method, the method comprising: determining whether a macroblock of a frame N transmitted after a skipped frame N- 1 is an inter type or a skipped type; allocating a new motion vector for the frame N according to a macroblock type of the skipped frame N- 1 when the macroblock of the frame N is an intra type; determining a new macroblock type for the frame N according to a macroblock type of the frame N- 1 located at approximately a similar position with the macroblock of the frame N when the macroblock of the frame N is the skipped type; determining a macroblock type of the skipped frame N- 1 when the macroblock of the frame N is the intra type; allocating an infinite motion vector to the macroblock of the frame N when the macroblock of the skipped frame N- 1 is an intra type; allocating the same motion vector of the macroblock of the frame N when the macroblock of the skipped frame N- 1 is a skipped type; and allocating a sum total of the motion vector allocated to macroblock of the frame N and the motion vector allocated to macroblock of the frame N- 1 as a new motion vector of the macroblock of the frame N when the macroblock of the skipped frame N- 1 is an inter type.

8. The method of claim 7 , further comprising: determining the macroblock type for the frame N- 1 located at approximately a similar position with the macroblock of the frame N when the macroblock of the frame N is the skipped type; determining the macroblock of the frame N as the intra type when the macroblock of the frame N- 1 is the intra type; determining the macroblock of the frame N as the skipped type when the macroblock of the frame N- 1 is the skipped type; and determining the macroblock of the frame N as the inter type when the macroblock of the frame N- 1 is the inter type.

9. The method of claim 8 , further comprising: allocating a motion vector about the macroblock of the frame N when the macroblock of the frame N is the inter type.

10. The method of claim 9 , wherein the motion vector is allocated so as to be similar to the motion vector of the macroblock of the frame N- 1 located at approximately a same position with the macroblock of the frame N.

11. A motion vector and macroblock type determining method, the method comprising: examining a macroblock of a frame N transmitted after a skipped frame N- 1 that is an inter type; determining a macroblock type of a frame N- 1 ; allocating a new motion vector for the macroblock of the frame N, according to the macroblock type of the frame N- 1 , wherein allocating the new motion vector comprises: allocating an infinite motion vector to the macroblock of the frame N when the macroblock of the skipped frame N- 1 is an intra type; allocating a motion vector of the macroblock of the frame N when the macroblock of the skipped frame N- 1 is a skipped type; and allocating an approximated sum total of the motion vector allocated to the macroblock of the frame N and the motion vector allocated to the macroblock of the frame N- 1 as a new motion vector for the macroblock of the frame N when the macroblock of the skipped frame N- 1 is the inter type.

12. The method of claim 11 , wherein the macroblock type of the frame N- 1 is divided into the intra type, the skipped type and the inter type.

13. The method of claim 11 , wherein the new motion vector is determined based on an equation MV′ N =MV N +MV N-1 , wherein MV′ N is a motion vector allocated to a macroblock of the frame N, MV N is a motion vector of a macroblock of the frame N, and MV N-1 is a motion vector of a macroblock of the frame N- 1 .

14. The method of claim 13 , wherein MV N-1 has an approximately infinite value when the macroblock of the frame N- 1 is the intra type.

15. The method of claim 13 , wherein MV N-1 has an approximately 0 value when the macroblock of the frame N- 1 is the skipped type.

16. A motion vector and macroblock type determining method, the method comprising: examining a macroblock of a frame N transmitted after a skipped frame N- 1 ; examining a macroblock type of a frame N- 1 located at approximately a similar position with the macroblock of the frame N; determining if the macroblock type of the frame N is same as the macroblock type of the frame N- 1 ; allocating an infinite motion vector to a macroblock of the frame N when the macroblock of the skipped frame N- 1 is an intra type; allocating a motion vector of the macroblock of the frame N when the macroblock of the skipped frame N- 1 is a skipped type; and to allocating an approximated sum total of the motion vector allocated to the macroblock of the frame N and the motion vector allocated to the macroblock of the frame N- 1 as a new motion vector for the macroblock of the frame N when the macroblock of the skipped frame N- 1 is an inter type.

17. The method of claim 16 , wherein the macroblock of the frame N is determined as an intra type, when the macroblock of the frame N- 1 is the intra type.

18. The method of claim 16 , wherein the macroblock of the frame N is determined as a skipped type, when the macroblock of the frame N- 1 is the skipped type.

19. The method of claim 16 , further comprising: determining the macroblock of the frame N as an inter type, when the macroblock of the frame N- 1 is an inter type; and allocating a new motion vector of the macroblock of the frame N.

20. The method of claim 19 , wherein a motion vector of the macroblock of the frame N- 1 located at approximately same position with the macroblock of the frame N is allocated as a new motion vector of the macroblock of the frame N.